Each year, over 1.5 million skin wounds are due to burns and over 1 million skin wounds are due to skin cancer. Each year, skin wounds result in about 75,000 inpatient cases and 12,000 deaths, and in 2005, about $3.3 billion dollars were spend on wound care.
In the body, skin wound healing involves fibroblast secretion of a provisional matrix, a process that usually begins 7 days post-injury. However, the currently available tissue engineered skin substitutes are decellularized human skin, such as alloderm, which are used for humans in cases of chronic skin wounds (e.g., due to diabetes, vasculitis, malnutrition, infection), acute skin wounds (e.g., burns, skin cancer), skin malformation, etc. Such decellularized skin substitutes lack adnexal structures (e.g., sebaceous glands, hair follicles, melanocytes), a rete ridge pattern at the epidermal-dermal junction, and other vital living components that promote wound healing. Furthermore, high risk of infection remains in heterologous transplantation of the currently available skin substitutes.
Since the regeneration of both dermal and epidermal skin layers are critical for successful wound healing with limited scar formation and infection, new models are needed that are “true” skin substitutes.